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With the aggravation of environmental pollution and the worldwide epidemic of infectious diseases, there is a higher demand for air filtration materials to intercept fine particulate matter and capture biological pollutants. Polypropylene (PP)/polycarbonate (PC) blends were melt blown and electrospun with polytetrafluoroethylene (PTFE) on their surfaces. The PP/PC/PTFE membranes structure with micro-nanostructure was constructed through the melt-blown layer with micron structure and the electrospun layer with the nanostructure. Carboxymethyl chitosan (CMCS) was loaded onto the surface of the PP/PC melt-blown layer. The synergistic effect of micro-nanostructure and CMCS can effectively capture PM2.5 and make the composite membrane have excellent antibacterial performance. The inhibition rates of PP/PC/PTFE composite membrane loaded with 5% CMCS against Staphylococcus aureus and Escherichia coli reached 81.54% and 86.1%, respectively. The filtration efficiency of PP/PC/PTFE composite membrane loaded with 5% CMCS is close to 100% for 0.25 μm particles, and the average filtration efficiency for 0.200–4.596 μm and 0.200–2.500 μm particles is 97.31% and 97.27%, respectively. After washing and drying five times, the corresponding inhibition rate only lost 16.52% and 4.24%. The micro/nano structure composite membrane prepared in this study has good antibacterial performance, high filtration efficiency, good stability, and is an excellent antibacterial high efficiency air filter. It provides a new idea for the preparation of air filter fiber composites.

The shortage of water resources and the aggravation of water pollution have become global environmental problems. The improvement of the separation performance and flux is still a key challenge that restrict the preparation of high-performance filtration membrane. The gradient structure fibrous membranes were designed and prepared using electrospinning nanofiber and polypropylene/low-melt- point polyester (PP/LPET) micro-fibrous and reinforced via needle-punching and hot-pressing. And the as-prepared membrane was functionalized and directly decorated by dopamine copolymerizes. The novel gradient membrane turned from a hydrophobic state to hydrophilic state, and had excellent mechanical and water transmission properties. Mostly importantly, the as-prepared hydrophilic gradient membranes showed durable oil-fouling repellency and the separation efficiency of oil/water mixture approximate 99% and the flux reach 10,278 ± 1512 L m−2 h−1. This method provides a feasible solution to overcome the high filtration resistance of electrospinning nanofiber membrane, as well as for the preparation of low-cost and high-performance composite membranes and structural regulation of functional membranes.

Photoelectrodes constructed with photoactive materials are of great significance for the performance of photoelectrochemical (PEC) sensors. In this study, a facile and efficacious non-enzymatic glucose sensor based on the Cu2O/TiO2 heterojunction was successfully constructed for quantitative determination of glucose concentration. The Cu2O/TiO2 heterojunction was generated by first obtaining TiO2 nanofibers via electrostatic spinning and high-temperature calcination, and then synthesizing Cu2O nanoparticles via a one-step hydrothermal reaction. By introducing the narrow band gap semiconductor Cu2O, the defect that pure TiO2 could not absorb visible light was improved, resulting in the improved photoelectrochemical performance of the composite material compared to the single component semiconductor. The sensor exhibited favorable PEC non-enzymatic glucose sensing performance under simulated sunlight irradiation with a wide linear response range from 1 mM to 14 mM (R2 = 0.9991) and a low detection limit of 14.4 μM (S/N = 3), along with good selectivity, stability and reproducibility. This also provided more ideas and possibilities for preparing photoelectrode materials by constructing heterojunctions.

In order to prepare a new high-performance and flexibility stab-resistant composite material, one type of high-toughness and high-strength hydrogel is combined with aramid fabric. In this paper, the nanocomposite (NC) hydrogels are prepared using Pluronic F127 Diacrylate (PF127DA) as the crosslinking agent, acrylamide as the monomer and nano-silica as nano additive. The influence of the addition amount of nano-silica on the toughness and strength of nano-composite hydrogels is discussed. The strength and toughness of the NC hydrogels with nano silica are higher than that of the acrylamide hydrogel without nano particles. The NC hydrogel with the best strength is made as a composite with aramid fabric and the effect of nanocomposite hydrogel on the stab resistance of the stab-resistant composite material is studied. The research shows that the stab resistance performance of the composite material prepared by aramid fabric and nanocomposite hydrogel is effectively improved in comparison with aramid fabric, and the yarn pulling force is also improved. The composite material with high stab resistance can be used as the stab-resistant layer of armor, cut-resistant gloves and stab-resistant base material of shoes. This work provided a possibility for preparing a kind of lightweight composite material with high stab resistance.

With the rapid development of wearable electronic products and smart devices, there is an urgent need to develop efficient electromagnetic interference (EMI)shielding materials to eliminate the resulting radiation pollution. Herein, hydrophobic and multi-responsive conductive composite film with core-shell structure and sandwich structure are constructed via simple in-situ polymerization and dip coating methods. The thin silicone coating can enhance the bonding fastness of the substrate and the conductive functional layer and endow the composite film excellent waterproof performance. The composite film with a thickness of 45 μm exhibits outstanding electrical conductivity of 62.15 S/cm and EMI shielding effectiveness (EMI SE) of 37.71 dB. Surprisingly, the composite film also exhibits good waterproof performance and excellent electro-optical thermal response, and has good stability in complex environments. This work proves the advantages of constructing multiple conductive interfaces inside the nanofiber film, and provides a new preparation strategy for efficient multifunctional shielding materials, which is expected to be widely used in the next generation of wearable electronic devices and wearable smart clothing.

We have synthesized a flexible polyurethane foam composite filled with expanded vermiculite powder and covered by concave-convex structural panel in order to improve the compression and cushioning property of PU foam. Concave-convex structural panel is that fabric cubes consisting of three layers of warp-knitted spacer fabrics arranged isometric apart between two layers of low-melting-point PET fabrics and then thermally processed at 180 °C. Effects of particle size and content of expanded vermiculite powders as well as the presence of concave-convex structural panel are examined in terms of foam structure and mechanical properties of composite PU foams. Expanded vermiculite addition decreases the energy required by pore nucleation, and the higher content of expand vermiculite results in pore diameter of foam and greater compression property. Filling of 2% vermiculites makes the compression property improved by 239% at 40% strain. Moreover, the smaller size of expanded vermiculite generates smaller and denser foam pore diameter and thus strengthened compression property. Foam composite with 800-mesh expanded vermiculites show the excellent compression property that 307% higher than neat PU foam at 40% strain. Concave-convex structural panel enhanced compression properties by 852% when fabric cubes arranged 1 cm apart and cushion efficiency by 29% compared to pure PU foam when fabric cubes arranged 4 cm apart. The resultant flexible polyurethane foam can absorb 97% energy at 12 J impact level. This composite can serve as the protective materials in kindergarten and old people's home.

Medical wound dressing with natural antibacterial efficacy is an important issue. However, few studies on Artemisia argyi oil based wound dressing have been studied because of the volatility of the Artemisia argyi oil. In this study, Artemisia argyi oil -microcapsules (AAO-MC)/PVC fibrous membrane were fabricated through emulsification-internal gelation and electrospinning method. The membranes were characterized by SEM, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and particle diameter, hydrophilicity, breathability, water vapor transmission rate (WVTR), and antibacterial performance were evaluated. The results show that AAO-MC microcapsules excellent stability, and the slow-release property. Moreover, the prepared AAO-MC/PVC fibrous membrane indicated good WVT (72.47 g/(m²·h)), high hydrophilicity (30.5°), and outstanding antibacterial rate (94.3%). This study provides a new strategy to prepare microcapsule nanofibrous membrane with excellent performance and is suggested to be a promising candidate for medical wound dressings.

In this study, we prepared a graded buffer composite by using shear thickening fluid (STF) capsules, polyurethane (PU) foam, and low-melting point PET fabric or spacer fabric with improved energy absorption performance. Various graded buffer composites are fabricated including STF capsule/PU foam covered with PET fabric (SC/PU/PET-CM) and STF capsule/PU foam covered with warp-knitted spacer fabric (SC/PU/WKSF-CM). The thermal stability and the mechanical properties of the graded buffer composite were tested. After adding STF capsules, PU foam still has good thermal stability whose weight- loss temperature reaches 200 ℃; and the compression energy and buffer performance both increases. The compression energy of S4-STF/PU is 2.26 times than that of S4-PU and 5.65 times than that of pure PU foam. Among SC/PU/PET-CM samples, HP-STF/PU graded foam composite showed the lowest impact force (3833 N). Comparatively, among SC/PU/WKSF-CM samples, the buffer performance of S4-STF/PU shows the best, and the impact value is reduced to 3921 N, which is 848 N lower (17.7%) than that of PU foam. The composites can be used as an alternative material in the field of protection.

Nowadays, various plastic products plays an important and indispensable role in our daily life. However, plastic cannot be essentially decomposed in the nature and thus led to inevitable damage to the environment. The study aims to recycle thermoplastic materials to attain the purposes of recycling, reuse, and sustainability. Polypropylene (PP) and toughening thermoplastic polyurethane (TTPU) are melt-blended for two cycles, which a small amount of compatibilizer (i.e. polypropylene grafted maleic anhydride, PP-g-MA) is added during the process. The morphology and mechanical properties of the PP/MA/TTPU blends are then measured and investigated. SEM images show that without the compatibilizer, TTPU particles demonstrate a dispersive phase in PP matrix. The presence of compatilizer improves the incompatible situation between TTPU and PP. The impact test results have proven that the incorporation of 20 wt% of TTPU and 5 wt% of compatibilizer helps to improve the interphase problem, thereby yielding the impact strength of 63.01 J/g. The tensile strength test results show that the presence of PP compensates for the insufficient rigidity and high production cost of TTPU. The flexural strength test results show that PP with high stiffness synergizes to the softness and flexural performance of TTPU. It is expected that using the secondary recovery process obtains the added value and sustainable use of plastic products, which is helpful to the sustainable development of the earth.

Metamaterials possess attractive electromagnetically left-handed properties yet their nature as an artificial structure rather than a material restricts their further applications. In this article we propose to use Co-based ferromagnetic microwires as periodical metamaterial units interweaved into a fabric to realize a “metacomposite” for steering wave propagation. By introducing ferromagnetic microwires in quartz fabric at three curvatures and periodic lengths, the electromagnetic response and microwave behaviors on both horizontally- and vertically-arranged directions were presented and investigated. Tensile behaviors of metacomposites with different ferromagnetic microwire morphologies were monitored by non-contact full field strain measurement system. At X band (8.2–12.4 GHz), metacomposites containing vertically-arranged ferromagnetic microwires show negative permittivity due to the dielectric resonance of microwire arrays. The dielectric response of metacomposites conformed to Lorentz-oscillator mode, behaving similarly to diluted plasma. When ferromagnetic microwires reached the lowest periodic curved length 2.5 mm with the highest curvature was obtained, the metacomposites presented the maximum microwave absorption of 34% and tensile stress of 273 MPa. The incorporation of ferromagnetic microwires exerts trivial influence on the mechanical properties yet homogenizes the strain and reduces the stress concentration on metacomposites. The metacomposite with a periodic curved length of 7.5 mm has less interweaving points and the highest surface float length, therefore achieving the maximum tensile strength of 458 MPa. The single negative metacomposites containing ferromagnetic microwires are featured with excellent structural properties and amenable microwave left-handed properties in controlling wave-propagating behavior, which is of practical engineering significance in structural health monitoring, sensing and stealth applications.

The traditional electrospinning needles are easily blocked and the processing is not suitable for mass production. In order to address the problems, this study uses a rotary linear electrode for electrospinning for the production of polyvinyl alcohol (PVA)/chitosan(CS)/graphene(Gr) nanofibrous membranes. The membranes are observed for micro-structure and tested for thermal stability, surface resistivity, and hydrophilicity, thereby examining the influence of the content of chitosan. The test results show that the presence of chitosan improves the hydrophilcity as well as affects the morphology of PVA/CS/Gr nanofibrous membranes where the nanofiber diameter is smaller. Moreover, FTIR results suggest that chitosan and PVA interact to generate hydrogen bonds that stabilize the thermal properties of nanofibrous membranes. In particular, the maximum thermal decomposition temperature of PVA/CS/Gr nanofibrous membranes composed of PVA/CS ratio being 9:1 is 297.7 ℃. Finally, using chitosan also increases the electrical conductivity and decreases the surface resistivity. This fabricated technique provides the possibility of mass-production of PVA/CS/Gr nanofibrous membranes in the future. Keywords: Rotary linear electrospinning, Nanofibrous membrane, Chitosan, Graphene, Thermal stability, Conductivity

In this study, impact-resistant polypropylene (MPP), thermoplastic polyurethane (TPU) and polypropylene-grafted maleic anhydride (MA) are made into MPP/TPU/MA blends using melt-compounding and injection methods. The blending morphology, crystallization behavior, and melting and thermal behaviors of the blends are evaluated in terms of the content of TPU and MA, examining the influences of the parameters. The scanning electron microscope (SEM) observation shows that 1 wt% of MA can effectively enhance the interfacial adhesion and compatibility between MPP and TPU. The differential scanning calorimetry (DSC) results show that the crystallization temperature and melting temperature of the blends are not dependent on the content of TPU or MA. However, using TPU and MA adversely affect the crystalline and melting enthalpy of the blends. The thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) curve both show that the higher the MPP, the greater the thermal stability of TPU. Likewise, using MA as compatibilizer also has a positive influence on the thermal stability of the blends. The X-ray diffraction (XRD) analyses confirm that the addition of TPU decreases the diffraction intensity of MPP, but does not harm the crystalline structure of MPP. Moreover, the addition of MA improves the compatibility between MPP and TPU. MA marginally decreases the peak value and does not influence the crystallinity degree of MPP. It is expected that the results of SEM, DSC, TGA, DTG, and XRD can serve as a valuable reference for the design of composites with improved thermal and crystallization behaviors. Keywords: Impact-resistant polypropylene, Thermoplastic polyurethane, Maleic anhydride, Thermogravimetric analysis, Derivative thermogravimetry, Blends, Crystallization